Synthetically Induced 1→4‐C Branching Motif ‐ An Access Towards Dense Urethane Connecting Dendritic Scaffolds and Application in Nuclear Track Detection

A series of dumbbell‐shaped urethane connecting polyoleifinic dendrimers, are synthesized from commercial AB2 monomer through the concept of post‐generative synthetic induction of novel 1→4‐C branching motif in divergent and convergent growth methodology using carbamoyl chloride reactivity. A synthetic protocol is conducted through the iterative process of O‐carbamoyl‐allylation of hydroxyls followed by Upjohn dihydroxylation of the allylic double bonds, leading to protection/deprotection free divergent pathway. In parallel, convergent growth route gains dendrimers in relatively good yields. Also, the process of O‐carbonyloxy‐allylation of [G‐1] polyol affords urethane‐carbonate framework providing access to 1→2‐C branching further. Incorporation of current branching motif results in dendritic scaffold with dense periphery at lower generations itself. Free radical cast polymerization of [G‐0.5] dendrimer with allyl diglycol carbonate (ADC) produces thermoset polymer films, showing good sensitivity and ability to permanently record nuclear tracks. The first example of post‐generative synthetic induction of novel “1→4‐C‐Urethane branching motif” from commercial N,N‐diallyl amine, AB2 monomer is shown. Current protection/deprotection free divergent growth methodology operates through an efficient two‐step iterative process of O‐carbamoyl‐allylation followed by Upjohn dihydroxylation to produce dense polyoleifinic dendritic scaffold with urethane connectivity.